Plastic bag roll

ABSTRACT

A roll of plastic bags having integral handles which can also be used to close each bag. The bags are formed as a continuous web of folded and flattened bags each joined to a longitudinally contiguous bag by a perforated severance line. The handles are defined by a cut-out region so that separation of the bags is effected by tearing the line of perforations only across a relatively short length.

BACKGROUND OF THE INVENTION

This invention relates to plastic bags which are provided on a roll tobe dispensed one at a time and, more particularly, to such a bag whichis formed with unitary handles which are also usable for closing thebag.

Conventionally, plastic bags used for holding trash or the like aremanufactured by extruding a tube of plastic material, expanding the tubewith air before the plastic has set, flattening the tube, formingtransverse heat seals and adjacent perforations at equally spacedintervals, and longitudinally folding and/or rolling up the flattenedtube for storage and transport in a dispensing carton. The bags areremoved one at a time from the dispensing carton by tearing them off theroll at the perforations.

When such a bag is filled, it is necessary to close it by utilizing aseparate tie. The use of a separate tie is disadvantageous for a numberof reasons. It is necessary to hold the bag closed with one hand whileapplying the tie with the other hand. The ties must be stored separatelyand can be misplaced. With overly full bags, the ties may be difficultto apply.

Various bag constructions have been proposed which incorporate integraltie strips. These constructions also possess numerous drawbacks. Theyrequire an additional act on the part of the user to tear away theintegral tie strip from the remainder of the bag. They also reduce theuseful capacity of the bag.

All of these constructions also require that the user separate the bagsby tearing the line of perforations across the entire width of the bag.When pulling a bag from a dispenser carton, this can pose difficulty fora user.

It would therefore be desirable to have a bag construction whichovercomes all of the drawbacks of these prior constructions.

SUMMARY OF THE INVENTION

According to the present invention there is provided a roll of plasticbags formed as a continuous web of folded and flattened bags each joinedto a longitudinally contiguous bag by a perforated severance line. Theweb is formed from a tubular plastic strip having a central longitudinalaxis and the sides of the strip are tucked in to form two equal inwardfolds, reducing the width of the strip by one half. The reduced widthstrip is folded in half along the central longitudinal axis so thatthere are eight layers of plastic material. The perforated severancelines are parallel one to the other, are equally spaced along the stripand are orthogonal to the central longitudinal axis of the strip. A pairof parallel heat seal lines flank each of the severance lines. A firstof the heat seal lines extends through all eight layers of the plasticmaterial and a second of the heat seal lines is formed of two heat seallines each of which extends through a respective four contiguous layersof the plastic material. Finally, there is a cut-out region through theeight layers which extends from the central longitudinal axis along eachseverance line a first predetermined distance and then substantiallyparallel to the central longitudinal axis a second predetermineddistance past the second heat seal line and then back to the centrallongitudinal axis. Accordingly, each first heat seal line is effectiveto seal the bottom of a respective bag, and each cut-out region andrespective adjacent second heat seal line is effective to form a pair ofhandles of a respective bag.

In accordance with an aspect of this invention, the first predetermineddistance is greater than one-half the width of the reduced width stripafter it has been folded in half.

In accordance with another aspect of this invention, the secondpredetermined distance is greater than the first predetermined distance.

According to this invention, there is provided a plastic bag formed froma folded tubular plastic strip. The plastic bag comprises a closedbottom end including a heat seal line extending through eight layers offolded plastic strip, and an open top end having a pair of spacedhandles. Each of the handles has a respective heat seal line extendingthrough a respective four contiguous layers of folded plastic strip andthe handles are separated by a cut-out region so that the handles extendpast an opening in the top end of the bag.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing will be more readily apparent upon reading the followingdescription in conjunction with the drawings in which like elements indifferent figures thereof are identified by the same reference numeraland wherein:

FIG. 1 is a perspective view showing a partially open bag constructedaccording to the present invention;

FIG. 2 is a plan view showing a portion of a roll of a continuous web ofbags according to the present invention;

FIG. 3 is a sectional view taken along the line 3-3 in FIG. 2;

FIGS. 4, 6, 8 and 10 illustrate steps during the manufacture of theinventive bags; and

FIGS. 5, 7 and 9 are sectional views taken along the lines 5-5, 7-7 and9-9 in FIGS. 4, 6 and 8, respectively.

DETAILED DESCRIPTION

As shown in FIG. 1, the inventive plastic bag 20 has a bottom end 22 anda transverse heat seal line 24 adjacent the bottom end 22. At theopposite end of the bag 20, there is an open top end 26 including a pairof handles 28,30, each with a respective transverse heat seal line32,34. As will become clear from the following discussion, the heat sealline 24 extends through eight layers of the plastic material forming thebag 20 and each of the heat seal lines 32,34 extends through arespective four contiguous layers of the plastic material. The handles28,30 can be tied together to close the open top end 26 of the bag 20,in addition to their use in assisting a user in holding the bag 20.

FIG. 2 shows a plurality of inventive bags 20 which have not yet beenseparated one from the other and which are wound into a roll 36. Thebags 20 are joined by, and may be separated at, lines of perforations 38between the heat seal lines 24 and 32,34. As is clear from FIG. 3, whenthe bag 20 is on the roll 36 and as it is unrolled from the roll 36, thebag 20 is folded to have eight layers of plastic material.

FIGS. 4-10 illustrate steps in the formation of the bag 20. As shown inFIGS. 4 and 5, the bag starts as a continuous endless tubular plasticstrip 40 traveling in the direction of the arrow 42. The strip 40 may beconsidered to have a central longitudinal axis 44 which is parallel tothe direction arrow 42. The first step in the formation of the bag 20 isto tuck in the two side edges 46,48 of the strip 40 to form two equalinward folds and reduce the width of the strip 40 by one half, as shownin FIGS. 6 and 7.

The strip 40 then passes through a first sealing and cutting mechanism(not shown) which forms the heat seal lines 32 and 34 and the cut-outregion 50. The heat seal lines 32 and 34 are co-linear (they arepreferably formed in a single step) and transverse (preferablyorthogonal) to the central longitudinal axis 44. Each of the heat seallines 32 and 34 extends through a respective four contiguous layers ofthe plastic material of the strip 40, as is clear from FIGS. 8 and 9.The cut-out region 50 is substantially rectangular and extends in twodirections away from the central longitudinal axis 44 substantiallyorthogonally thereto a first predetermined distance “a” along the line22, and then substantially parallel to the axis 44 a secondpredetermined distance “b” past the heat seal lines 32 and 34, and thenback to the axis 44 along the line 26 orthogonally to the axis 44.Preferably, the first predetermined distance from the axis 44 along theline 22 is greater than one-half the width of the strip 40 after theside edges 46,48 have been tucked in. Also preferably, the secondpredetermined distance (i.e., the distance between the lines 22,26) isgreater than the first predetermined distance.

The final step in the formation of the bag 20 is illustrated in FIG. 10.As shown therein, the strip 40 is folded in half along the centrallongitudinal axis 44 so that it comprises eight layers of plasticmaterial. The strip 40 then passes through a second sealing and cuttingmechanism (not shown) which forms the heat seal line 24 and the line ofperforations 38, both of which extend through all eight layers of thestrip 40. The heat seal line 24 and the line of perforations 38 are bothtransverse to the axis 44 and preferably are orthogonal thereto. Theline of perforations 38 is between the heat seal lines 24 and 32,34 andis aligned with the line 22 of the cut-out region 50. After this finalformation step, the finished strip 40 is rolled up to form the roll 36,which may comprise a desired number of bags 20. On the roll 36, the bagsare so configured that the bottom end 22 of each bag is further into theroll 36 than the top end 26. The roll 36 may then be placed into anappropriate carton for storage, shipment and dispensing.

In use, a bag 20 is pulled from the roll 36 by the handles 28,30 untilthe line of perforations 38 at its bottom end 22 is exposed. The bagwhich was pulled from the roll is then separated from the next bag inthe roll by tearing along the line of perforations 38. An advantage ofthe disclosed construction is that only a relatively short line ofperforations needs to be severed, due to the cut-out region 50, which isalso effective to provide separate handles 28,30.

Accordingly, there has been disclosed an improved roll of plastic bags.While a preferred embodiment of the inventive plastic bag has beendisclosed, it will be appreciated by those of skill in the art thatvarious adaptations and modifications to the disclosed bag are possible.It is therefore intended that this invention be limited only by thescope of the appended claims.

1. A roll of plastic bags formed as a continuous web of folded and flattened bags each joined to a longitudinally contiguous bag by a perforated severance line, wherein: the web is formed from a tubular plastic strip having a central longitudinal axis; the sides of the strip are tucked in to form two equal inward folds reducing the width of the strip by one half; the reduced width strip is folded in half along the central longitudinal axis so that there are eight layers of plastic material; the severance lines are parallel one to the other and are equally spaced along the strip; the severance lines are orthogonal to the central longitudinal axis of the strip; a pair of parallel heat seal lines flank each of the severance lines, wherein a first of the heat seal lines extends through all eight layers of the plastic material and a second of the heat seal lines is formed of two heat seal lines each of which extends through a respective four contiguous layers of the plastic material; and there is a cut-out region through the eight layers which extends from the central longitudinal axis along each severance line a first predetermined distance and then substantially parallel to the central longitudinal axis a second predetermined distance past the second heat seal line and then back to the central longitudinal axis; whereby each first heat seal line is effective to seal the bottom of a respective bag, and each cut-out region and respective adjacent second heat seal line is effective to form a pair of handles of a respective bag.
 2. The roll according to claim 1 wherein the first predetermined distance is greater than one-half the width of the reduced width strip after it has been folded in half.
 3. The roll according to claim 2 wherein the second predetermined distance is greater than the first predetermined distance.
 4. The roll according to claim 1 wherein the two heat seal lines of the second heat seal line are co-linear.
 5. A plastic bag formed from a folded tubular plastic strip, comprising: a closed bottom end including a heat seal line extending through eight layers of folded plastic strip; and an open top end having a pair of spaced handles each having a respective heat seal line extending through a respective four contiguous layers of folded plastic strip, the handles being separated by a cut-out region so that the handles extend past an opening in the top end of the bag.
 6. The plastic bag according to claim 5 wherein the cut-out region is substantially rectangular. 